Magnesia cement.



PATENT OFF] (ill.

.\ murmur-Virus MAGNESIA CEMENT.

Specification of Letters Patent.

Patented Jan. 12,1909.

Application fllvd December 30. 1907. Serial No. 408,487.

'1") all 'wlunn it may COILMIMJ Be it known that l, (Anurrux Burns, a citizen of thc limtcd Status, residing at .Lztrchmont. in the county of Wcsiclmstvr and State of New York, hnrc invcnicd (rerts n. now and uscful lrnprovclncnts in Mag nvsin Cmncnt, of which the following: is a spccihcatmn.

'llus invent-ion rclatcs to cenwnl nmtcrml in the form of a dry powder comprising oxid 5 oi'magncsia, and the like, and has for ns olnccl n (:rmcnt nnltcrml which will set to a haul tough stone-lilo) cmnpositioh rm'rcly by the addition of ntcr.

The prcwnt adnpiniiiims of ihcold Sorel cement campus-i1 ion ,g cncridly call for the ad- Mixture of uiiltl of magnesia with sawdust. infusqrial mirth, sand and the like, together with coloring matter, an in the admixturc with this dry powdcr of a concentrated aqueous solution of chlorid of nmgncsiunl at tho {point where the cement is to he used.

'i to employment of soliitions of magnesrnm cl'uorid has often times been found dis- :nlvantagcous and objectionable, and more or less endeavor has been made to secure a cement which is light in color, or may be delicutciy tinted, thatwill set properly on admixture with water; hence the eflorts to produce a white Port-land cemcnt; also the vn'iploimcnt of barium chlorid and magnesium sulfate and magnesia 0 "id in admixture. in itc of: the fairly satisfactory whitc Portland cements which have been produced,

"- thou are not obtainable with these mixtures solid objects which have the degree of transluccncy desired for some purposes, and my 'compo-sition, as hereinafter described, aflords a material which has this desirable property. My composition consists of a dry substan tially. non-hydroscopic powder, comprisin- -,-Xi(l of magnesia, or equivalent oxid, an saline bodie-sca )able of gradually rcacting'in tho presence oi water to formv magnesium r :h1orid, -or cquivalent compound. Ada ita- (ion may also be made of the same procet ure {0 the production of cements containing oxid of calc um; or with oxid of zinc, alumina,

9%.,101' dental fillings,- all with or without fibrous material such as sawdust or asbestos.

in order to eliminate the use of the liquid solutions of chlorid, I employ with the oxid of nmgncsia, dry materials w rich are capablc of gradually reacting to form chlo ds, as for instance, a mixture of common salt and sulfatc ol" nuuzncsia, or of conunon salt and sul' futc of zinc, or of potassium chlorid and snl l'nic of lllttfIllt'Slit, and tho like. The rcaction of tho coumonents of such mixtnrcs'prmlnccs mugnrsium chlorid and sodium sulfate; a. rc-

att-iHn which normally progresscs only to a certain incousiderablc point, and quantitatively, the fOIIllDlllLlfl of magnesium chlorid being dc )endcnt on the mass or concentration of tic sodium chlorid and magnesium sulfate.

The cm'j'ncratiun of two principlcs is sc icurcd in the present cmnposilion, namely, the law of mass action, which iudn'utvs llu' product of any reaction as [-rnjnntiuhul lo the masses of. thc reacting constitm-ms, and gsecond, the law of scgwgntion, which indi- ,cntcs that the removal of a body from tho field of rcuction through precipitation, or lot-hcrwisc, will 'allow an otherwise incom- )lete rcaction' to'progress to completion. lence, with mixtures of sodium chlorid,

magnesium sulfatc and magnesium oxid, tho magnesium chlorid formed in small amount 5 by wetting the mixture with water soon combines with the magnesium oxid to form E the rather insoluble oxy chlorid of magnef sium; thus removing the previously formed l magnesium clllorid from the field of reaction. Conse ucntly magnesiun' chlorid must bc' formeil anew to-supply the void, as it may be termed, and this so formed chlorid, in turn combines with additional oxid oi magnesia, and thus the reaction continues until a large proportion of the chlorid has combined with the ma ncsia.

Suita )lc compositions illustrating my invention are made by mixing,

Common salt, dried and pow- The above formula: illustrate the charactor of my invention, but it should be understood that. variations may be madc to a considerable extent, dcpnn ing on the character of the material desired, and also on the purity of the chemicals employed. The substitution of zinc oxid and sulfate in the above formulae affords very hard cements. In the case of the common salt mixtures it should be borne in mind that the mass action of the salt is an important factor in the production of a firmly setting translucent cement.

The cements above illustrated may be prepared in the form of dry owders andare ready for use merelyb t 1e admixture of suflicient water to pror uce a Jlastic mass. Galcined gypsum, etc., may be added to modify the set.

Various other sulfates than those enumerated may be used, as well'as various chlorids, the object being to provide metathe'tically reacting matcrlals, which give rise to the'gradual production of the ox chlorul of magnesia when water is added t \ereto.

'hat I claim is 1. A dry substantially non-hydroscopic powder, comprisin oxid of magnesium and saline bodies caps )10 of gradually reacting in the simultaneous presence of in'atcr, and said oxid to form chlorid of magnesium; whereby setting qualities are conferred upon the composition, due to the formation of oxy chlorid of magnesium.

2. A dry substantially non-hydroscopic powder, comprisin oxid of magnesium and saline bodies cap ab e of slowly metathetically reacting in'the presence of water, and said oxid, to form ma nesium chlo'rid.

3. A dry pow er capable of setting on the addition of water, to form a hard translucent material, which comprises a metallic oxid such as the oxid of ma nesium or zinc, and saline bodies capable o reacting in the presence of water and said oxid, to form a chlorid; whereby oxy chlorids are produced conferring setting properties upon the cornposltion.

4. As a cement composition, a dry powder, comprlsing oxid of ma nesium and a salt such as magnesium su fate, together with a substantlal amount of an alkali ehlorid such as sodium chlorid.

5. As a cement composition, a dry powder, comprising a. mixture of oxid of magnesium, sulfate of magnesium and chlorid of sodium.

6. A cement com osition, comprisin oxid of magnesium wit 1 approximately equa arts oi sodium chlorid and magnesium sulate.

7. A- cement composition, comprising oxid of magnesium, su fate of magnesium, a substantial amount of chlorid of sodium, sand and a fibrous materialsuch as sawdust or asbestos. i

8. A. cement material suitable for flooring, wall plaster and the like, consisting of a'dry substantial non-hydrosco ic powder, com prising fibrous material sub 1 as sawdust and' asbestos incor )orated with magnesium oxid,

magnesium. su fate and sodium chlorid.

9. As a ccmentcomposition, a dry powder, comprising oxid of ma nesium and a salt such as magnesium su fate, to ether with a substantial amount of an al alinc chlorid such as sodium chlorid; all free from alkaline earth chlo ids.

In testimony wlereof I have affixed my signature in presence of two Witnesses.

- OARLETON ELLIS. Witnesses NATHANIEL L. FOSTER, HENRIETTA BERKWITZ. 

